Air-heated vaporizer

LNG Vaporization, Pressure Regulation and Metering Skid-Mounted System

The LNG (Liquefied Natural Gas) vaporization, pressure regulation and metering skid-mounted system is an integrated, modular natural gas processing equipment. It integrates the functions of LNG unloading, pressurization, vaporization, pressure regulation, metering and odorization, and is widely used in urban gas supply, industrial fuel replacement, transportation gas filling and other scenarios. The following is a detailed introduction from the aspects of technical principles, core configurations, functional features, application fields and industry trends:

I. Technical Principles and Core Processes

Unloading and Storage

LNG in the tank truck is pressurized into the storage tank through the unloading and pressurization vaporizer. The storage tank adopts a vacuum insulation design (with a daily evaporation rate < 0.3%) and can stably store LNG at a low temperature of -196℃. The storage tank is equipped with safety valves, liquid******/pressure sensors to ensure that the pressure is controlled within 1.2MPa.

Vaporization and Reheating

LNG in the storage tank is vaporized using ambient heat through the air-temperature vaporizer. In cold northern regions, a forced reheater (such as an electric heating water bath heater) needs to be configured to ensure that the temperature of the vaporized natural gas is ≥ 5℃. The vaporization capacity can be designed as 50,000 - 200,000 cubic meters per day according to requirements.

Pressure Regulation and Metering

The vaporized natural gas is stabilized to the pressure required by the user (e.g., 0.4 - 1.6MPa) through a pressure regulator, and metering with an accuracy of ±1.0% is achieved through a mass flowmeter. The odorization device automatically adds odorant (such as tetrahydrothiophene) according to the flow signal to meet the safety warning requirements for natural gas.

BOG and EAG Treatment

The boil-off gas (BOG) from the storage tank is returned to the pipeline network through a recovery system or stored in a BOG tank; the vented low-temperature natural gas (EAG, Emergency Annular Gas) is heated to above -107℃ by a heater and then discharged at high altitude through a flame arrester and a vent tower to avoid low-temperature frostbite and safety risks.

II. Key Configurations and Technical Parameters

Core Equipment

Storage Tank: Vacuum powder insulated horizontal/vertical storage tank, with a volume of 50 - 300 cubic meters, a design pressure of 1.6MPa, and an operating temperature of -162℃.

Vaporizer: The air-temperature vaporizer is made of low-temperature resistant stainless steel (304/316L), with a vaporization capacity of 500 - 5,000 cubic meters per hour; the forced reheater has a power of 15 - 60kW and is suitable for extremely cold environments of -40℃.

Pump Skid: The low-temperature submersible liquid pump has a flow rate of 0 - 640L/min and a motor power of 15 - 30kW, with automatic pump shutdown protection for over-temperature/over-pressure.

Control System: The PLC intelligent control cabinet integrates remote monitoring, data acquisition and safety interlock functions, supporting mobile APP operation and cloud data analysis.

Technical Parameters

Processing Capacity: 50,000 - 200,000 cubic meters per day (per station).

Operating Pressure: Inlet 0.4 - 0.8MPa, outlet 0.1 - 1.6MPa.

Temperature Range: -196℃ (LNG storage tank) to 55℃ (outlet gas).

Metering Accuracy: ±1.0% (mass flowmeter).

Explosion-Proof Grade: Ex db eb IIB T4 Gb, complying with the GB 50058 explosion-proof standard.

III. Design Features and Advantages

Modular Integration

All equipment is integrated into standardized skids or containers. After prefabrication in the factory,***** pipeline connection and power supply are required on-site. The installation period is shortened to 1 - 2 weeks, and the floor area is reduced by 40% - 60%. For example, a 20-foot container skid-mounted system can integrate a storage tank, pump skid, vaporizer and gas filler, suitable for mobile gas filling scenarios.

Intelligence and Automation

Remote Monitoring: Real-time monitoring of pressure, temperature, flow and other parameters through the Internet of Things (IoT) platform. Automatic alarm and emergency shutdown are triggered in case of abnormalities.

Unmanned Operation: Automatic unloading, pressure regulation, metering and BOG recovery, reducing manual intervention and lowering operation and maintenance costs.

Intelligent Docking: The latest products adopt visual recognition technology to achieve millimeter-level positioning of tank truck flanges and fully automatic loading/unloading, improving operational efficiency by 40%.

Safety and Reliability

Multiple Protections: More than 20 safety measures including low-temperature safety valves, emergency shut-off valves, combustible gas detectors and electrostatic grounding.

Material and Technology: Low-temperature pipelines are welded by argon arc welding, and 100% of the welds are subject to radiographic testing (qualified at****** II). The service life of the vacuum insulation layer is ≥ 10 years.

Emergency Response: Equipped with an independent EAG venting system and backup power supply, which can maintain safe operation for 4 hours in case of power failure.

Economy and Flexibility

Investment Cost: The construction cost of a single station is approximately 800,000 - 2,000,000 RMB, which is more than 50% lower than that of traditional fixed gas filling stations.

High Mobility: The skid-mounted equipment can be relocated as a whole, adapting to the needs of temporary gas supply and emergency peak shaving. For example, the 100,000 cubic meters per day skid-mounted equipment of Furuitec Energy Services in Xinjiang realized cross-regional relocation of 5,000 kilometers through modular disassembly and was put into operation quickly.

Energy Conservation: The air-temperature vaporizer does not require additional energy consumption, saving more than 80% of electricity compared with the water bath vaporizer.

IV. Application Fields and Typical Cases

Urban Gas Supply

It provides LNG cylinder group gas supply for residential communities and commercial complexes not covered by the pipeline network, replacing bottled liquefied petroleum gas (LPG) and reducing gas consumption costs by more than 30%. For example, the skid-mounted gas supply station built by Hebei Tairan Technology for a community in Nangong City supplies an average of 5,000 cubic meters of gas per day, meeting the needs of 2,000 households.

Industrial Fuel Replacement

It provides clean fuel for enterprises in ceramics, glass, food processing and other industries, replacing coal-fired boilers and reducing SO₂ emissions by more than 90%. The 200,000 cubic meters per day skid-mounted project of Inner Mongolia Delong Energy processes 66 million cubic meters of natural gas annually, which can replace 220,000 tons of coal and reduce CO₂ emissions by 550,000 tons.

Transportation Gas Filling Network

Skid-mounted gas filling stations are built in highway service areas and logistics parks to provide refueling services for LNG heavy trucks. The intelligent skid-mounted equipment at Sinopec Longkou LNG Receiving Station realizes rapid gas filling in 3 - 5 minutes and serves more than 200 vehicles per day on average.

Emergency and Peak Shaving Support

It is quickly deployed when the supply and demand of natural gas are unbalanced to ensure civil gas use. During the winter of 2024, the skid-mounted station put into operation by ENN Energy in an industrial park in Zhejiang increased the daily gas supply capacity by 150,000 cubic meters, alleviating the regional gas supply tension.

V. Industry Standards and Certifications

Domestic Standards

LNG Skid-Mounted Gas Filling Device (Q/ZXJ 03-193-2024): Specifies the design, manufacturing and acceptance requirements of the equipment, including 98 indicators such as the static evaporation rate of the storage tank and pipeline welding process.

GB/T 18442 Fixed Vacuum Insulated Cryogenic Pressure Vessels: Specifies the vacuum degree, insulation performance and test methods of the storage tank.

GB 50156 Technical Standard for Automobile Refueling and Gas Filling Stations with Hydrogen Refueling Facilities: Regulates the fire separation distance, electrical explosion protection and safety facility configuration of skid-mounted stations.

International Certifications

ASME BPVC VIII-1 (American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section VIII-1)

CE Certification (EU Pressure Equipment Directive)

ISO 9001 Quality Management System Certification

VI. Market Trends and Outlook

Policy-Driven Growth

China's "dual carbon" goals (carbon peaking and carbon neutrality) promote the replacement of coal with natural gas. In 2024, the central government allocated 5.79 billion RMB in subsidies for skid-mounted gas supply projects. It is expected that the market scale will reach 9.6 billion RMB in 2025, with an annual growth rate of 11.2%.

Technological Innovation and Upgrading

Intelligence: AI algorithms optimize the vaporization process, and predictive maintenance reduces equipment failure rates.

Low-Carbonization: Pilot projects of hydrogen blending (e.g., 10% hydrogen + 90% LNG) reduce nitrogen oxide emissions by 12%.

Cold Energy Utilization: The cold energy from LNG vaporization is used in cold chain logistics and air separation, improving the comprehensive energy efficiency by 20%.

Expansion of Application Scenarios

Rural Gasification: The "rural gasification" policy promotes the extension of skid-mounted stations to counties and towns. It is expected that 550 new stations will be added by 2025.

Biogas to LNG: The biomethane liquefaction skid-mounted equipment of Wanhao Energy can convert livestock manure into LNG, processing 300,000 tons of waste annually and reducing CO₂ emissions by 70,000 tons.

VII. Selection Suggestions and After-Sales Service

Selection Key Points

Gas Consumption Scale: Select the storage tank volume (50 - 300 cubic meters) and vaporizer specification according to the user's average daily gas consumption.

Environmental Conditions: A forced reheater needs to be configured in cold regions, and anti-corrosion coatings should be used in coastal regions.

Scalability: Reserve interfaces for BOG recovery, hydrogen blending, etc., to adapt to future demand upgrades.

After-Sales Service

Warranty Period: 2-year warranty for core equipment (storage tank, pump skid) and lifetime maintenance for the control system.

Emergency Response: Technical support within 2 hours and spare parts delivery to the site within 48 hours (national warranty).

Regular Maintenance: Comprehensive inspection once a year (including vacuum degree testing and safety valve calibration) to extend the equipment service life to more than 15 years.